• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.171-174
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• 2011

In this paper, transformed IFA design is proposed to improve the antenna gain of GSM/DCS/PCS band. New antenna structure has been approved to be more convenient matching in the mobile phone terminal and increase gains and expansion bandwidth through the simulation and real measurement. According to measurement, it's shown 1.57dB higher average gain than conventional IFA.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.1
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• pp.58-66
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• 2003

This paper discusses the practical issue of the bias estimation of the KOREASAT ground tracking data. First, a batch filter based orbit determination algorithm including the turn around range measurement in addition to the range, azimuth and elevation measurement is presented. Then the estimation performance is analyzed through simulation studies. Additionally, this paper proposes a tracking antenna bias estimation strategies using accurately tuned secondary ground tracking station. Finally the relationship between antenna biases are analyzed to give comprehensive tool for estimation results evaluation.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.433-436
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• 2008

In this paper, a novel compact broadband dual frequency microstrip antenna is presented. The meander type patch has been designed to have dual resonant frequencies, and the ground with slot was employed to expand the bandwidth in WCDMA band. The simulated results were obtained using HFSS, and the measurement on the proposed antenna was conducted in an anechoic chamber equipped with a network analyzer and a far field measurement system. As a result, measured maximum gain of antenna is 2.07$\sim$2.87 dBi in the GSM band and 3.91$\sim$5.61 dBi in the WCDMA band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.7
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• pp.653-659
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• 2016

This paper proposes an ultra-wideband Log-Periodic Dipole Array(LPDA) antenna for the feeder of a reflector antenna to be used for airborne spinning direction-finding and detecting wideband signals. To obtain the ultra-wideband characteristics over the 20:1 bandwidth from S to Ka band, the radiation elements of the antenna were printed on a substrate and a wedge-typed dielectric supporter with robust structure was inserted between the substrates. Also, the center portion of the supporter was replaced by a styrofoam material to reduce the supporter weight. The 5-dB return loss of the designed LPDA antenna showed ultra-wideband characteristics, which are 37.57:1(1.09~40.95 GHz) in the simulation and 33.85:1(1.31~44.35 GHz) in the measurement. We achieved the required gains of 5.78 dBi in the simulation and 5.76 dBi in the measurement in the operating band. The proposed robust, light-weight, and ultra-wideband LPDA antenna confirmed that it can be applied for airborne applications.

• Journal of electromagnetic engineering and science
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• v.17 no.3
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• pp.133-137
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• 2017

In this study, a 28-GHz U-slot array antenna for a wideband communication system is proposed. The U-slot patch antenna structure consists of a patch, two U-shaped slot, and a ground plane. With the additional U-slot, the proposed antenna has around 10% of bandwidth at -10 dB. To increase gain, the U-slot antenna is arrayed to $2{\times}2$. The proposed antenna is designed and fabricated. The $2{\times}2$ array antenna volume is $41.3mm{\times}46mm{\times}0.508mm$. The proposed antenna was measured and compared with the simulation results to prove the reliability of the design. The bandwidth and gain of the measurement results are 3.35 GHz and 13 dBi, respectively and the operating frequency is around 28 GHz.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.2
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• pp.257-260
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• 2014

In this paper, a high gain waveguide array antenna combining horn antenna on slot radiator was designed. And the fabricated antenna showed enough gain, improved efficiency and broadband characteristics for receiving satellite signals, compare to conventional microstrip antenna which has dielectric loss and radiation loss on transmission line. For easy fabrication, the waveguide structure was composed by 3-stages of radiator, signal coupler and transmission line. By experiment, the array waveguide antenna of 4 by 16 showed 28.3[dBi] gain and 2:1 of VSWR. And by combining horn antenna structure, the gain was increased 1[dB]. The received signal from Koreasat 6 by measurement showed 16[dBc] of C/N on BS(Broadcasting Satellite)-band and 14[dBc] of C/N on CS(Communication Satellite)-band.

• Journal of information and communication convergence engineering
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• v.12 no.1
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• pp.1-7
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• 2014

A novel design of a simple circular ring with open-ended monopole antenna for wireless local area network (WLAN) applications is proposed in this article. The proposed antenna consists of an open-ended circular ring and $50-{\Omega}$ microstrip feed-line. The proposed antenna is capable of generating two separate resonant modes with good impedance-matching conditions. A prototype of the proposed antenna is designed, fabricated, and measured. Acceptable agreement between the measurement and simulation results is achieved. Experimental results show that the proposed antenna has operating bandwidths of 1.99-3.04 GHz and 5.08-6.1 GHz with a return loss of less than -10 dB, covering the required bandwidths of the 2.4/5.2/5.8-GHz WLAN standards. This is a microstrip antenna for IEEE 802.11a/b wireless local area networks applications. Meanwhile, the two-dimensional (2D) radiation patterns and three-dimensional (3D) gain performance of the antenna are also observed and discussed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.112-115
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• 2016

This paper demonstrates a scalp-implantable miniaturized antenna at the medical implant communication service (MICS) (402-405MHz) band. The antenna size is only $27.63mm^3$($8.5mm{\times}6.5mm{\times}0.5mm$), which is the smallest antenna for the MICS band. Miniaturization is achieved by using a symmetrical serpentine shaped radiating patch and placing open-end slots in the ground plane. In addition, co-axial feeding is used for excitation with a shorting pin connected between the radiator and ground. The antenna was simulated in a homogeneous skin model and in the human scalp. An experimental prototype of the proposed antenna was fabricated and measured in a skin-mimicking gel. Good agreement was obtained between the measurement and simulation results, showing a broad bandwidth of 49 MHz (from 395 to 444 MHz) for |S11| less than -10 dB and a maximum gain of -42.87 dBi. This gain is higher than the previous MICS antenna with respect to antenna size.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.5
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• pp.279-285
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• 2004

In this paper, low noise amplifier(LNA), aperture coupled patch antenna and $4{\times}4$ array antenna are designed in the frequency range from 11.7㎓ to 12㎓. Array antennas with and without LNA at the antenna element are fabricated and the performances are measured including noise figure(NF). The noise figure calculation for overall system was conducted and compared with the measured data to verify our measurement method. The measured overall noise figure of the array antenna with LNA at the antenna element is lower than that of array without LNA as expected.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.7
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• pp.625-634
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• 2016

A full digital receiving active phased array antenna generates final receiving beams by digital beam forming of received digital signals in element-level that makes difficult to use typical near-field measurement method. Thus in this paper, a modified near-field measurement method which is suitable for full digital receiving active phased array antenna is proposed. Also the measured results of receiving beam pattern and G/T using developed L-band full digital receiving active phased array antenna are shown for the verification of proposed method.